The purpose of the program is to expand the ability of the Chicago Department of Public Health (CDPH) to perform surveillance of the prevalence of atypical strains of HIV, including drug resistant strains and non-B subtypes, by piloting the use of dried blood spots. CDPH is conducting a CDC-funded study to conduct studies of atypical and resistant HIV strains in persons newly diagnosed with HIV using remnant serum from the diagnostic specimen. This study, "Variant, Atypical and Resistant HIV Surveillance (VARHS)," is currently being implemented at eight sites in Chicago. However, some diagnostic sites and clinical centers in Chicago cannot be included in that surveillance effort due to logistical problems with specimen availability, specimen processing time, or staff acceptance. The sites selected for this project represent a diverse range of testing settings and encompass a wide geographic area of Chicago. Location types include hospitals, neighborhood clinics, community centers, late-night street corners, needle exchange programs, outreach sites, and drug rehabilitation centers. This diversity will provide a unique opportunity to conduct atypical HIV surveillance activities in non-health care settings, and may more accurately represent all persons newly diagnosed with HIV in Chicago. Moreover, data from this project will enhance the ability of CDPH to conduct surveillance for resistant and atypical HIV strains. Because of Chicago's very large immigrant population, the ability to monitor atypical strains is especially valuable. Our objectives are to: (1) monitor the prevalence of HIV drug resistant strains and non-B HIV-1 subtypes in persons newly diagnosed with HIV in public and private settings in Chicago, including those in which sera are not available for HIV genotyping and those in which sera are used.; (2) compare the results of HIV genotyping for atypical strain surveillance purposes from both a serum specimen and a dried blood spot collected not more than three months after HIV diagnosis; (3) compare the prevalence of atypical strains of HIV among persons diagnosed at sites where remnant sera from HIV diagnostic specimens are used for HIV drug resistance and subtype surveillance, and sites where remnant sera cannot be used, such as sites where sera is not used for HIV diagnosis, sites where phlebotomy volumes for HIV testing specimens are consistently below the 1 ml minimum of remnant serum for HIV genotyping for the purpose of atypical strain surveillance, sites where the use of sera from the diagnostic blood draw for HIV genotyping is not practical because the time between blood draw and processing is consistently greater than 96 hours rendering the amplification of virus for HIV drug resistance genotyping problematic, and sites where the use of dried blood spots (DBS) for atypical HIV strain surveillance is more acceptable than the use of sera to staff or participants, or where fewer resources may be required to collect DBS than sera; and (4) evaluate the resources needed and the logistics involved in collecting and transporting specimens and amplifying HIV for genotyping from DBS, compared with using HIV diagnostic sera, for routine atypical HIV strain surveillance.